Size of the output buffer. It needs to be at least
as big as the expected result depending on the operation
After operation it will be updated with the actual size of the
result.
In case of error where the dst sgl size was insufficient,
it will be updated to the size required for the operation.

Function performs a sign operation as defined by public key
algorithm. In case of error, where the dst_len was insufficient,
the req->dst_len will be updated to the size required for the
operation

verify

Function performs a sign operation as defined by public key
algorithm. In case of error, where the dst_len was insufficient,
the req->dst_len will be updated to the size required for the
operation

encrypt

Function performs an encrypt operation as defined by public key
algorithm. In case of error, where the dst_len was insufficient,
the req->dst_len will be updated to the size required for the
operation

decrypt

Function performs a decrypt operation as defined by public key
algorithm. In case of error, where the dst_len was insufficient,
the req->dst_len will be updated to the size required for the
operation

set_pub_key

Function invokes the algorithm specific set public key
function, which knows how to decode and interpret
the BER encoded public key

set_priv_key

Function invokes the algorithm specific set private key
function, which knows how to decode and interpret
the BER encoded private key

max_size

Function returns dest buffer size required for a given key.

init

Initialize the cryptographic transformation object.
This function is used to initialize the cryptographic
transformation object. This function is called only once at
the instantiation time, right after the transformation context
was allocated. In case the cryptographic hardware has some
special requirements which need to be handled by software, this
function shall check for the precise requirement of the
transformation and put any software fallbacks in place.

exit

Deinitialize the cryptographic transformation object. This is a
counterpart to init, used to remove various changes set in
init.